Its also a slim possibility that the fuel pressure regulator could be bad...very slim chance though. In my time selling parts and working on cars I may sell 1 fpr for every 100 fuel pumps. Try checking the fuel pressure anyways to rule that out.
Yes, some leaking header flanges (stock manifolds)
Looking to get some headers, was notified from a forum member that he had a set of stainless headers. SS atr type headers
I will check tps, upgrading ignition, module to. 886/87
The header cracks could be causing a part of your problem. If exhaust escapes before the O2 sensor then it'll be read as being leaner than what it really is and the ECM will make adjustments. Also if the O2 sensor is shot that can cause it to run rich. Im still learning about TR's myself, but mine has already taught me alot in the short time its been running.